Merrlam Four New Mammals from Mexico. 81 



Genus Teanopus nob. 



Type, Teanopus phenax gen. et. sp. nov. 



Characters. Size of a middle-sized wood rat (Neotoma), which it 

 greatly resembles, though externally still more like Hodomys vetulus; 

 ears large and nearly naked; tail long and densely covered with short 

 hairs; soles of fore and hind feet, between pads, completely scutellate 

 everywhere covered with small tubercles. Skull in general like that 

 of Neotoma and Teonoma, but audital bullae enormously inflated verti 

 cally, subwheel-shaped, blunt anteriorly, nearly parallel, almost ex 

 actly as in Xenomys; antorbital slits very large and broadly open; sphe 

 noid vacuities open; braincase without temporal shield. Lower jaw 

 with distinct prominence over root of incisor; angle elongate, its lower 

 border strongly inflected and upturned, forming a long shallow trough as 

 in Teonoma, but less extreme; infracondylar notch deeper than in either 

 Neotoma or Teonoma. Last lower molar with reentrant enamel loop on 

 inner side passing obliquely forward in front of its mate on outer side, 

 thus approaching the condition in Hodomys. 



Teanopus phenax sp. nov. 



Type from Camoa, Rio Mayo, Sonora. No. 95,841 9 ad., XL S. National 

 Museum, Biological Survey Collection. November 4, 1898. E. A. Gold 

 man. Original No. 13,258. 



Characters. Size and general appearance of Hodomys vetulus; tail 

 rather long and black or dusky all round; upperparts buffy gray; under- 

 parts yellowish white anteriorly, underfur showing through posteriorly; 

 top and sides of nose dusky; cheeks pale grayish; outer side of foreleg to 

 wrist grayish dusky, sharply contrasted with white of underside; hind 

 foot soiled whitish above; ankles and sides of heel dusky on both sides, 

 bordered with white below. 



Dental characters. Molars (except the last lower, described in the gen 

 eric diagnosis) with enamel folds as in the albigula group of Neotoma. 



Measurements. Type specimen, 9 ad - : total length 352; tail vertebras 

 172; hind foot 37.5. Average of 3 from type locality: total length 365; 

 tail vertebrae 183; hind foot 37.7. 



Platygeomys tylorhinus angustirostris subsp. nov. 



Type from Patamban, Michoacan, Mexico. No. 125,688 9 ad., U. S. 

 National Museum, Biological Survey Collection. February 2, 1903. 

 Nelson and Goldman. Original No. 15,850. 



